Automotive data recording devices exist which collect and record information from an engine computer. One known device is disclosed in U.S. Pat. No. 190 5,541,840 issued to Gurne, et al. The device disclosed in Gurne, et al is a hand-held device that has many functions, one of them being a data logger. As a data logger, the device monitors pre-determined variables and stores them in an internal memory. Since the device's memory is limited, the logged data is stored in memory using a shift register concept. That is, as new data is logged, older data is over-written. Therefore, in the device's memory, the logging information stored represents a snapshot, or a window, of information. Thus, only a limited amount of data can be recorded.
A second known device is disclosed in U.S. Pat. No. 190 4,602,127 issued to Neely, et al. The device in Neely, et al hooks up to an on-board computer and monitors pre-determined variables. The data is then read serially into memory, such as a magnetic tape. The data stored on the magnetic tape can then be used for diagnostic purposes at a remote station. Because a magnetic tape storage mechanism is used, data collection is slow and limited.
Since most driving conditions cannot be reproduced in a garage environment, it is desirable to record vehicle operation data while driving. Since some problems are intermittent, it is often desirable to record data over a long period of time. Furthermore, since it may be difficult to determine the root cause of a problem, it is desirable to record a wide variety of vehicle data. Such data would be helpful in diagnosing vehicle problems, performing vehicle research, and many other functions. Thus, there exists a need for a portable data-recording device capable of collecting a large amount of data and storing the data for subsequent processing.